It’s funny how excited a little bit of glacier ice can get you when you’re out on the debris. We selected the site of the AWS and wind tower because it appeared to be representative of the glacier and it was in an area that was relatively flat. In the past, most flat areas have had very large boulders/debris and the debris was very thick (> 1 m). This morning when we started to dig, I had very little faith that the site we selected was going to have a “measurable” debris thickness. Once you get to 0.5 m and especially once you hit 1 m, it gets incredibly difficult to manually dig any deeper. Therefore, I was shocked / stunned / ecstatic(!) when we dug beneath the net radiation sensor and found the debris thickness to be 42 cm – what luck! I guess it’s the little things that make you happy, right?
We installed our temperature sensors, which allow us to determine how the heat from the surface propagates through the debris and eventually melts the glacier, and got started marking the area for the Structure from Motion work that we’ll be doing soon. The one thing we learned today was that the wind makes everything very chilly. We woke up to clear skies and were expecting a sunny and warm day, but with 5 m/s winds constantly blowing in our face, it made things a bit unpleasant. We got a bit of work done and then headed back to our camp a bit early for some training with the GPR equipment.
GPR refers to ground penetrating radar and is a technique that is used to measure and detect objects beneath the surface. In our case, we’ll be trying to measure the ice thickness of the glacier. The quick and dirty of GPR is you have a transmitter and a receiver. The transmitter sends a great deal of energy into the ground, which then reflects off various surfaces, e.g., we should see a strong reflection at the ice/rock interface, and this reflected signal is then picked up by the receiver. Sounds easy right? Things become a bit more difficult when you get onto a debris-covered glacier and everything must be carried or dragged across the surface. This requires a lot of people such that the antennas don’t get stuck on the boulders, everyone must be walking at the same speed, and all the electrical connections must be secure. Back to electronics my forte!
Daene has typically taken the lead with the GPR work as the one and only time I did it was in September of 2013, so it’s been a while. However, you’ve got to roll with the punches, so today was practicing our setup and having everyone get a feel for the equipment. Fortunately, things went very well and I’m looking forward to what we come up with tomorrow – granted it’s going to be utterly exhausting walking all over the glacier at 5000+ meters with batteries, antennas, computers, and other wires/cords somehow attached to our backpacks, but I absolutely can’t wait. It’s the little things right?